Toxicity of high-molecular-weight polyethylene glycols in Sprague Dawley rats

Insights into the Pharmacokinetics, Biodistribution, and Oral Toxicity of a Polymeric Benzimidazole - Curcumin Nanocomplex with a Multitarget Anticancer Potential

The current study investigates the oral toxicity of a PEGylated β-cyclodextrin-curcumin functionalized benzimidazole nanocomplex (BMPE-Cur) with multitarget anticancer potential in Swiss albino mice. Acute and chronic toxicities were evaluated after oral administration of BMPE-Cur in single doses ranging between 0.5-2.5 g/kg and repeated dosing of 5, 10, and 25 mg/kg for 28 consecutive days, respectively. Pharmacokinetic (PK) and biodistribution profiles of BMPE-Cur were analyzed by LC-MS. The toxicological assessments revealed that BMPE-Cur was tolerable up to 2.5 g/kg, with moderate organosomatic and biochemical alterations associated with doses >1.5 g/kg, whereas repeated dosing induced dose-dependent histopathological, hematological, and biochemical alterations. Doses within a range of 5-10 mg/kg were well tolerated, as indicated by the general normalization of the mentioned parameters. PK analysis revealed a similar value of maximum plasma concentration (Cmax) attained by the free BMPE and BMPE-Cur. However, the latter accelerated the time to reach Cmax (Tmax) by 50%, concomitant with longer residence time and lower clearance rate. BMPE-Cur also presented excellent hemocompatibility with human blood, with 46.58%-99.96% lower hemolysis than free BMPE within the same concentration range. These findings underscore the favorable pharmacokinetics and biocompatibility of BMPE-Cur while identifying safe therapeutic doses for potential human translation.

The Art of PEGylation: From Simple Polymer to Sophisticated Drug Delivery System

The development of effective drug delivery systems (DDSs) is important for cancer and infectious disease treatment to overcome low bioavailability, rapid clearance and the toxicity of the therapeutic towards non-targeted healthy tissues. This review discusses how PEGylation, the attachment of poly(ethylene glycol) (PEG) molecules to nanoparticles (NPs), enhances drug pharmacokinetics by creating a "stealth effect". We provide the synthesis methods for several PEG derivatives, their conjugation with NPs, proteins and characterization using modern analytical tools. This paper focuses particularly on covalent conjugation and self-assembly strategies for successful PEGylation and discusses the influence of PEG chain length, density and conformation on drug delivery efficiency. Despite the PEGylation benefits, there are several challenges associated with it, including immunogenicity and reduced therapeutic efficacy due to accelerated blood clearance. Therefore, the balance between PEGylation benefits and its immunogenic risks remains a critical area of investigation.

Site-Selective Zwitterionic Poly(caprolactone-carboxybetaine)-Growth Hormone Receptor Antagonist Conjugate: Synthesis and Biological Evaluation

Zwitterionic polymers have been found to be biocompatible alternatives to poly(ethylene glycol) (PEG) for conjugation to proteins. This work reports the site-selective conjugation of poly(caprolactone-carboxybetaine) (pCLZ) to human growth hormone receptor antagonist (GHA) B2036-alkyne and investigation of safety, activity, and pharmacokinetics. Azide-end-functionalized pCLZs were synthesized and conjugated to GHA B2036-alkyne via copper-catalyzed click reaction. The resulting inhibitory bioactivity concentration responses in Ba/F3-GHR cells were compared to those of PEGylated GHA B2036. IgG and IgM antibody production was tested in mice, and no measurable antibody or cytokine production was detected for the pCLZ conjugate. Using 18F-labeled PET/CT imaging, the pCLZ conjugate showed an increase in circulation time compared to that of GHA B2036. Acute toxicity of the polymer was investigated in vivo and found to be nontoxic. Ex vivo degradation of the polymer on the conjugate was investigated. The results suggest that pCLZ-GHA is a potentially safe alternative to PEG-GHA.

Polyethylene Glycols Stimulate Ca2+ Signaling, Cytokine Production, and the Formation of Neutrophil Extracellular Traps

Purpose

Given the increased use of polyethylene glycol (PEG) in refining the therapeutic activity of medicines, our research focuses on explaining the potential mechanism of immune reactions associated with this polymer. We aim to investigate the interaction of different types of PEG with mouse and human immune cells, thereby contributing to understanding PEG interactions with the immune system and verifying the proinflammatory activity of the tested polymers.

Patients and Methods

Mouse macrophage and neutrophil cell lines, human peripheral blood mononuclear cells, and polymorphonuclear cells isolated from healthy donors were exposed to various PEGs. ROS, NO, and cytokine production were analyzed using fluorescence intensity, absorbance, or cytometric measurements. Toll-like receptor (TLR) signaling was verified using HEK-blue-reporter cell lines. Finally, neutrophil trap formation was studied using immunofluorescence labeling, and calcium imaging was performed using a Ca2+-sensitive indicator and fluorescence microscope.

Results

Our findings show that specific PEG and mPEG are not toxic to tested mouse and human cells. However, they exert proinflammatory activity against human immune cells, as evidenced by the increased secretion of proinflammatory cytokines, such as IFN-a2, IFN-γ, TNF-α, MCP-1, IL-8, IL-17A, and IL-23. This phenomenon is independent of PEG signaling via TLR. Additionally, mPEG10 induced the formation of neutrophil extracellular traps and intracellular calcium signaling.

Conclusion

Our finding suggests that some PEG types have proinflammatory activity against human immune cells, manifesting in the upregulated production of cytokines and neutrophils trap releasing.

Insights into the Chemical Exposome during Pregnancy: A Non-Targeted Analysis of Preterm and Term Births

Human-made chemicals are ubiquitous, leading to chronic exposure to complex mixtures of potentially harmful substances. We investigated chemical exposures in pregnant women in New York City by applying a non-targeted analysis (NTA) workflow to 95 paired prenatal urine and serum samples (35 pairs of preterm birth) collected as part of the New York University Children's Health and Environment Study. We analyzed all samples using liquid chromatography coupled with Orbitrap high-resolution mass spectrometry in both positive and negative electrospray ionization modes, employing full scan and data-dependent MS/MS fragmentation scans. We detected a total of 1524 chemical features for annotation, with 12 chemicals confirmed by authentic standards. Two confirmed chemicals dodecyltrimethylammonium and N,N-dimethyldecylamine N-oxide appear to not have been previously reported in human blood samples. We observed a statistically significant differential enrichment between urine and serum samples, as well as between preterm and term birth (p < 0.0001) in serum samples. When comparing between preterm and term births, an exogenous contaminant, 1,4-cyclohexanedicarboxylic acid (tentative), showed a statistical significance difference (p = 0.003) with more abundance in preterm birth in serum. An example of chemical associations (12 associations in total) observed was between surfactants (tertiary amines) and endogenous metabolites (fatty acid amides).

Recent Progress of Small Interfering RNA Delivery on the Market and Clinical Stage

Small interfering RNAs (siRNAs) are promising therapeutic strategies, and five siRNA drugs have been approved by the Food and Drug Administration (FDA) and the European Commission (EC). This marks a significant milestone in the development of siRNA for clinical applications. The approved siRNA agents can effectively deliver siRNAs to the liver and treat liver-related diseases. Currently, researchers have developed diverse delivery platforms for transporting siRNAs to different tissues such as the brain, lung, muscle, and others, and a large number of siRNA drugs are undergoing clinical trials. Here, these delivery technologies and the latest advancements in clinical applications are summarized, and this Review provides a concise overview of the strategies employed for siRNA delivery to both hepatic and extrahepatic tissues.

Striving for Uniformity: A Review on Advances and Challenges To Achieve Uniform Polyethylene Glycol

Poly(ethylene glycol) (PEG) is the polymer of choice in drug delivery systems due to its biocompatibility and hydrophilicity. For over 20 years, this polymer has been widely used in the drug delivery of small drugs, proteins, oligonucleotides, and liposomes, improving the stability and pharmacokinetics of many drugs. However, despite the extensive clinical experience with PEG, concerns have emerged related to its use. These include hypersensitivity, purity, and nonbiodegradability. Moreover, conventional PEG is a mixture of polymers that can complicate drug synthesis and purification leading to unwanted immunogenic reactions. Studies have shown that uniform PEGylated drugs may be more effective than conventional PEGylated drugs as they can overcome issues related to molecular heterogeneity and immunogenicity. This has led to significant research efforts to develop synthetic procedures to produce uniform PEGs (monodisperse PEGs). As a result, iterative step-by-step controlled synthesis methods have been created over time and have shown promising results. Nonetheless, these procedures have presented numerous challenges due to their iterative nature and the requirement for multiple purification steps, resulting in increased costs and time consumption. Despite these challenges, the synthetic procedures went through several improvements. This review summarizes and discusses recent advances in the synthesis of uniform PEGs and its derivatives with a focus on overall yields, scalability, and purity of the polymers. Additionally, the available characterization methods for assessing polymer monodispersity are discussed as well as uniform PEG applications, side effects, and possible alternative polymers that can overcome the drawbacks.

Lipid nanoparticles for siRNA delivery in cancer treatment

RNA-based therapies, and siRNAs in particular, have attractive therapeutic potential for cancer treatment due to their ability to silence genes that are imperative for tumor progression. To be effective and solve issues related to their poor half-life and poor pharmacokinetic properties, siRNAs require adequate drug delivery systems that protect them from degradation and allow intracellular delivery. Among the various delivery vehicles available, lipid nanoparticles have emerged as the leading choice. These nanoparticles consist of cholesterol, phospholipids, PEG-lipids and most importantly ionizable cationic lipids. These ionizable lipids enable the binding of negatively charged siRNA, resulting in the formation of stable and neutral lipid nanoparticles with exceptionally high encapsulation efficiency. Lipid nanoparticles have demonstrated their effectiveness and versatility in delivering not only siRNAs but also multiple RNA molecules, contributing to their remarkable success. Furthermore, the advancement of efficient manufacturing techniques such as microfluidics, enables the rapid mixing of two miscible solvents without the need for shear forces. This facilitates the reproducible production of lipid nanoparticles and holds enormous potential for scalability. This is shown by the increasing number of preclinical and clinical trials evaluating the potential use of siRNA-LNPs for the treatment of solid and hematological tumors as well as in cancer immunotherapy. In this review, we provide an overview of the progress made on siRNA-LNP development for cancer treatment and outline the current preclinical and clinical landscape in this area. Finally, the translational challenges required to bring siRNA-LNPs further into the clinic are also discussed.

The interplay between PEGylated nanoparticles and blood immune system

During the last two decades, an increasing number of reports have pointed out that the immunogenicity of polyethylene glycol (PEG) may trigger accelerated blood clearance (ABC) and hypersensitivity reaction (HSR) to PEGylated nanoparticles, which could make PEG modification counterproductive. These phenomena would be detrimental to the efficacy of the load and even life-threatening to patients. Consequently, further elucidation of the interplay between PEGylated nanoparticles and the blood immune system will be beneficial to developing and applying related formulations. Many groups have worked to unveil the relevance of structural factors, dosing schedule, and other factors to the ABC phenomenon and hypersensitivity reaction. Interestingly, the results of some reports seem to be difficult to interpret or contradict with other reports. In this review, we summarize the physiological mechanisms of PEG-specific immune response. Moreover, we speculate on the potential relationship between the induction phase and the effectuation phase to explain the divergent results in published reports. In addition, the role of nanoparticle-associated factors is discussed based on the classification of the action phase. This review may help researchers to develop PEGylated nanoparticles to avoid unfavorable immune responses based on the underlying mechanism.

High strength, controlled release of curcumin-loaded ZIF-8/chitosan/zein film with excellence gas barrier and antibacterial activity for litchi preservation

Polysaccharide films containing protein additives have good application prospects in agriculture and food field. However, interfacial incompatibility between hydrophobic proteins and hydrophilic polymers remains a major technical challenge. In this work, the interfacial compatibility between hydrophobic zein and hydrophilic chitosan (CS) is improved by the chemical crosslinking between zinc ions of curcumin-loaded zeolitic imidazolate framework-8 (Cur-ZIF-8) with CS and zein. With the improvement of interface compatibility, the results show that the elongation at break and O₂ barrier property of synthesized Cur-ZIF-8/CS/Zein are 9.2 and 1.5 times higher than CS/Zein, respectively. And the Cur-ZIF-8/CS/Zein exhibits superior antibacterial and antioxidant properties as well. Importantly, Cur-ZIF-8/CS/Zein can also be used as an intelligent-responsive release platform for curcumin. As a result, Cur-ZIF-8/CS/Zein can keep the freshness and appearance of litchi at least 8 days longer than that of CS/Zein. Therefore, this study provides a novel method to improve the interfacial compatibility between hydrophobic proteins and hydrophilic polymers, and is expected to expand the application of protein/polymer composites in agriculture and food field.

Normal Neurodevelopment and Fertility in Juvenile Male Rats Exposed to Polyethylene Glycol Following Dosing With PEGylated rFIX (Nonacog Beta Pegol, N9-GP): Evidence from a 10-Week Repeat-Dose Toxicity Study

N9-GP/Rebinyn®/Refixia® is an approved PEGylated (polyethylene glycol-conjugated) recombinant human factor IX intended for prophylactic and/or on-demand treatment in adults and children with haemophilia B. A juvenile neurotoxicity study was conducted in male rats to evaluate effects on neurodevelopment, sexual maturation, and fertility following repeat-dosing of N9-GP. Male rats were dosed twice weekly from Day 21 of age with N9-GP or vehicle for 10 weeks, followed by a dosing-free recovery period for 13 weeks and terminated throughout the dosing and recovery periods. Overall, dosing N9-GP to juvenile rats did not result in any functional or pathological effects, as measured by neurobehavioural/neurocognitive tests, including motor activity, sensory function, learning and memory as well as growth, sexual maturation, and fertility. This was further supported by the extensive histopathologic evaluation of brain tissue. Exposure and distribution of polyethylene glycol was investigated in plasma, choroid plexus, cerebrospinal fluid, and brain sections. PEG did not cross the blood brain barrier and PEG exposure did not result in any effects on neurodevelopment. In conclusion, dosing of N9-GP to juvenile rats did not identify any effects on growth, sexual maturation and fertility, clinical and histological pathology, or neurodevelopment related to PEG exposure and supports the prophylactic use of N9-GP in children.